One of the most promising courses for further technological development in chemical, pharmaceutical, cosmetic, refining, food products, and many other areas relates to the production of emulsions and dispersions having the smallest possible particle sizes with the maximum size uniformity. Moreover, during the creation of new products and formulations, the challenge often involves the production of two, three, or more complex components in disperse systems containing particle sizes at the submicron level. Given the ever-increasing requirements placed on the quality of dispersing, traditional methods of dispersion that have been used for decades in technological processes have reached their limits. Attempts to overcome these limits using these traditional technologies are often not effective, and at times not possible.
Hydrodynamic cavitation is widely known as a method used to obtain free disperse systems, particularly lyosols, diluted suspensions, and emulsions. Such free disperse systems are fluidic systems wherein dispersed phase particles have no contacts, participate in random beat motion, and freely move by gravity. Such dispersion and emulsification effects are accomplished within the fluid flow due to cavitation effects produced by a change in geometry of the fluid flow.
Hydrodynamic cavitation is the formation of cavities and cavitation bubbles filled with a vapor-gas mixture inside the fluid flow or at the boundary of the baffle body resulting from a local pressure drop in the fluid. If during the process of movement of the fluid the pressure at some point decreases to a magnitude under which the fluid reaches a boiling point for this pressure, then a great number of vapor-filled cavities and bubbles are formed. Insofar as the vapor-filled bubbles and cavities move together with the fluid flow, these bubbles and cavities may move into an elevated pressure zone. Where these bubbles and cavities enter a zone having increased pressure, vapor condensation takes place withing the cavities and bubbles, almost instantaneously, causing the cavities and bubbles to collapse, creating very large pressure impulses. The magnitude of the pressure impulses within the collapsing cavities and bubbles may reach 150,060 psi. The result of these high-pressure implosions is the formation of shock waves that emanate from the point of each collapsed bubble. Such high-impact loads result in the breakup of any medium found near the collapsing bubbles.
A dispersion process takes place when, during cavitation, the collapse of a cavitation bubble near the boundary of the phase separation of a solid particle suspended in a liquid results in the breakup of the suspension particle. An emulsification and homogenization process takes place when, during cavitation, the collapse of a cavitation bubble near the boundary of the phase separation of a liquid suspended or mixed with another liquid results in the breakup of drops of the disperse phase. Thus, the use of kinetic energy from collapsing cavitation bubbles and cavities, produced by hydrodynamic means, can be used for various mixing, emulsyfying, homogenizing, and dispersing processes.
Devices are known in the art which utilize the passage of a hydrodynamic flow through a cylindrical flow-through chamber internally accommodating a baffle body installed across and confronting the direction of hydrodynamic flow to produce varied cavitation effects. The baffle element provides a local contraction of the flow as the fluid flow confronts the baffle element thus increasing the fluid flow pressure. As the fluid flow passes the baffle element, the fluid flow enters a zone of decreased pressure downstream of the baffle element thereby creating a hydrodynamic cavitation field.
Once such prior art device is described in U.S. Pat. No. 5,492,654 issued on Feb. 20, 1996 to the Applicant herein and other named inventors and is hereby incorporated by reference herein. The cavitation device of the '654 Patent identifies the art as utilizing a cylindrical flow-through chamber internally accommodating a plurality of baffles elements, wherein the upstream baffle elements have a larger diameter than the downstream baffle elements. Such a device is utilized in an attempt to create and control hydrodynamic cavitation in fluids wherein the position of the baffle elements is variable. However, there is an ever-increasing need to create and control hydrodynamic cavitation to a greater degree.